crystal report barcode font free Behavioral Object-Oriented Design in VB.NET

Printer Quick Response Code in VB.NET Behavioral Object-Oriented Design

Behavioral Object-Oriented Design
Making QR-Code In VB.NET
Using Barcode printer for Visual Studio .NET Control to generate, create QR image in .NET framework applications.
www.OnBarcode.com
Read QR-Code In Visual Basic .NET
Using Barcode scanner for .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
It is a common trap to think that data in objects needs to be normalized like it is in a database. A better way to think about objects is to say that behavior should be normalized. The goal of objectoriented design is to avoid replication of behavior, not data. At this point, most people are struggling. Most developers have spent years programming their brains to think relationally, and this view of object-oriented design flies directly in the face of that conditioning. Yet the key to the successful application of object-oriented design is to divorce object thinking from relational or data thinking. Perhaps the most common objection at this point is this: if two objects (for example, CustomerEdit and InvoiceEdit) both use the same data (for example, the customer s name), how do you make sure that consistent business rules are applied to that data And this is a good question. The answer is that the behavior must be normalized. Business rules are merely a form of behavior. The business rule specifying that the customer name value is required, for instance, is just a behavior associated with that particular value. Earlier in the chapter I discussed the idea that a validation rule can be reduced to a method defined by a delegate. A delegate is just an object that points to a method, so it is quite possible to view the delegate itself as the rule. Following this train of thought, every rule then becomes an object. Behavioral object-oriented design relies heavily on the concept of collaboration. Collaboration is the idea that an object should collaborate with other objects to do its work. If an object starts to become complex, you can break the problem into smaller, more digestible parts by moving some of the sub-behaviors into other objects that collaborate with the original object to accomplish the overall goal.
Drawing PDF 417 In VB.NET
Using Barcode encoder for VS .NET Control to generate, create PDF417 image in VS .NET applications.
www.OnBarcode.com
Painting Code 3/9 In VB.NET
Using Barcode creation for Visual Studio .NET Control to generate, create Code 39 Full ASCII image in Visual Studio .NET applications.
www.OnBarcode.com
C HAPTE R 2 FRA MEWORK DES IGN
Barcode Creation In VB.NET
Using Barcode encoder for VS .NET Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
2D Barcode Creator In VB.NET
Using Barcode printer for .NET framework Control to generate, create Matrix 2D Barcode image in .NET applications.
www.OnBarcode.com
In the case of a required customer name value, there s a Rule object that defines that behavior. Both the CustomerEdit and InvoiceEdit objects can collaborate with that Rule object to ensure that the rule is consistently applied. As you can see in Figure 2-6, the actual rule is implemented only once but is used as appropriate effectively normalizing that behavior.
Encode EAN / UCC - 13 In Visual Basic .NET
Using Barcode generator for Visual Studio .NET Control to generate, create EAN128 image in VS .NET applications.
www.OnBarcode.com
Generate Identcode In Visual Basic .NET
Using Barcode printer for Visual Studio .NET Control to generate, create Identcode image in VS .NET applications.
www.OnBarcode.com
Figure 2-6. Normalizing the customer name required behavior It could be argued that the CustomerName concept should become an object of its own and that this object would implement the behaviors common to the field. Although this sounds good in an idealistic sense, it has serious performance and complexity drawbacks when implemented on development platforms such as .NET. Creating a custom object for every field in your application can rapidly become overwhelming, and such an approach makes using technologies such as data binding very complex. My approach of normalizing the rules themselves provides a workable compromise: providing a high level of code reuse while still offering good performance and allowing the application to take advantage of all the features of the .NET platform. In fact, the idea that a string value is required is so pervasive that it can be normalized to a general StringRequired rule that can be used by any object with a required property anywhere in an application. In 11, I implement a CommonRules class containing several common validation rules of this nature.
Generate QR-Code In Objective-C
Using Barcode creation for iPhone Control to generate, create QR image in iPhone applications.
www.OnBarcode.com
Make QR-Code In None
Using Barcode printer for Office Word Control to generate, create Denso QR Bar Code image in Microsoft Word applications.
www.OnBarcode.com
Object-Relational Mapping
PDF-417 2d Barcode Creation In Visual Studio .NET
Using Barcode printer for .NET Control to generate, create PDF 417 image in .NET framework applications.
www.OnBarcode.com
Print Barcode In VS .NET
Using Barcode generation for .NET framework Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
If object models aren t the same as relational models (or some other data models you might be using), some mechanism is needed by which data can be translated from the Data Storage and Management layer up into the object-oriented Business layer.
Code 39 Reader In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Barcode Generation In Visual Studio .NET
Using Barcode drawer for ASP.NET Control to generate, create Barcode image in ASP.NET applications.
www.OnBarcode.com
Note This mismatch between object models and relational models is a well-known issue within the objectoriented community. It is commonly referred to as the impedance mismatch problem, and one of the best discussions of it can be found in David Taylor s book, Object-Oriented Technology: A Manager s Guide (Addison-Wesley, 1991).
DataMatrix Generator In VS .NET
Using Barcode encoder for Visual Studio .NET Control to generate, create Data Matrix 2d barcode image in .NET framework applications.
www.OnBarcode.com
Universal Product Code Version A Maker In Visual C#.NET
Using Barcode encoder for VS .NET Control to generate, create UPC A image in .NET applications.
www.OnBarcode.com
Several object-relational mapping (ORM) products from various vendors, including Microsoft, exist for the .NET platform. In truth, however, most ORM tools have difficulty working against object models defined using behavioral object-oriented design. Unfortunately, most of the ORM tools tend to create superpowered DataSet equivalents, rather than true behavioral business objects. In other words, they create a data-centric representation of the business data and wrap it with business logic. The differences between such a data-centric object model and what I am proposing in this book are subtle but important. Responsibility-driven object modeling creates objects that are focused on the object s behavior, not on the data it contains. The fact that objects contain data is merely a side
GS1 128 Drawer In Java
Using Barcode creation for Java Control to generate, create UCC.EAN - 128 image in Java applications.
www.OnBarcode.com
PDF-417 2d Barcode Printer In None
Using Barcode creator for Font Control to generate, create PDF-417 2d barcode image in Font applications.
www.OnBarcode.com
GTIN - 12 Drawer In None
Using Barcode encoder for Font Control to generate, create GS1 - 12 image in Font applications.
www.OnBarcode.com
Making Barcode In Visual C#.NET
Using Barcode printer for .NET framework Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.